British Foreign Secretary Boris Johnson raised the case of a detained dual national on Sunday when he met with Iranian President Hassan Rouhani during a two-day trip to Tehran.
The British Foreign Office says Johnson raised the case of Nazanin Zaghari-Ratcliffe, who is serving a five-year prison sentence for allegedly plotting against Iran's government, during a "worthwhile visit" to the country.
The Foreign Office said both Johnson and Rouhani "spoke forthrightly" during their nearly hour-long meeting and "agreed on the need to make progress in all areas," without elaborating.
Zaghari-Ratcliffe's husband says she faces trial on new charges Sunday that carry the possibility of an additional 16-years imprisonment, but Iranian judiciary spokesman Gholamhosein Mohseni Ejehi said last month that her verdict has been finalized.
Efforts to free Nazanin Zaghari-Ratcliffe, a charity worker who has been held since April 2016, are believed to top Johnson's agenda. Johnson recently complicated those efforts by saying incorrectly that she was training journalists when arrested. He has since apologized.
London is considering repaying Tehran some 400 million pounds from a pre-1979 arms deal. Both sides say the money isn't related to Zaghari-Ratcliffe.
Johnson met with Ali Akbar Salehi, the head of Iran's nuclear program, earlier Sunday.